Enhancing activated sludge dewaterability is of scientific and engineering importance in the face of accelerated urbanization and stringent environmental regulations. In this study, we investigated the integration of acidification and ultrasound (A/US) treatment for improving sludge dewaterability at both bench- and pilot-scales. Our results showed that the A/US process exhibited significantly improved sludge dewatering performance, characterized by capillary suction time, cake moisture, and water/solid content of sludge cake. Synergistic dewatering mechanisms were elucidated with a suite of macro and spectroscopic evidence. Characterization of treated sludge revealed that US-induced thermal, mechanical shearing force, and radical oxidation effects disrupts floc cells and accelerates the decomposition of extracellular polymeric substances (EPS), releasing bound water into the bulk phase. In addition to enhancing hydrolysis of EPS, the acidic pH environment caused the protonation of functional groups on EPS, facilitating the reflocculation of US decomposed sludge for improved filterability. Our bench-scale and pilot-scale investigations provide a mechanistic basis for better understanding of the A/US process, and enable development of a viable and economical dewatering technology.

中文翻译：

---

了解酸化和超声处理活性污泥脱水之间协同作用的机理：从试验台到中试研究

面对加速的城市化进程和严格的环境法规，提高活性污泥的脱水能力具有科学和工程意义。在这项研究中，我们研究了酸化和超声处理（A / US）的集成，以在基准规模和中试规模上提高污泥的脱水能力。我们的结果表明，A / US工艺具有显着改善的污泥脱水性能，其特点是毛细管抽吸时间，滤饼水分和污泥饼的水/固体含量。借助一系列宏观和光谱学证据阐明了协同的脱水机理。对处理后的污泥的表征表明，美国诱导的热，机械剪切力和自由基氧化作用破坏了絮凝细胞，并加速了细胞外聚合物质（EPS）的分解，将结合水释放到本体相中。除了增强EPS的水解作用外，酸性pH环境还导致EPS上的官能团质子化，从而促进了US分解污泥的再絮凝，从而提高了可过滤性。我们的实验室规模和中试规模的调查为更好地了解A / US过程提供了机械基础，并有助于开发可行且经济的脱水技术。